Don’t Out-Eat Your Running: How to Train Consistently and Still Lose Weight

by Jim Richardson | Last Updated: April 28, 2020

It’s a common problem for runners — you’re hitting the pavement three to five days per week, but you’re not losing weight. In fact, you may even be slightly heavier than when you started training. 

Photo by Leon Liu on Unsplash

The reason is simple: you’re out-eating your running. Although it seems counterintuitive, it’s shockingly easy to eat more calories than you burn. Fortunately, with the right strategies, it’s possible to eat enough to fuel your runs while maintaining enough of a calorie deficit to drop excess weight.

Calculate Your Calorie Burn

The first step in losing weight through running is to know how many calories your body burns at rest. This number is your basal metabolic rate or BMR. Calculating your BMR is simple using the Mifflin St. Jeor Equation:

Women: 10 x weight (kg) + 6.25 x height (cm) – 5 x age (years) – 161 

Men: 10 x weight (kg) + 6.25 x height (cm) – 5 x age (years) + 5

Once you find your BMR, multiply it by 1.2 to find the number of calories you burn during a day that includes mostly seated work and light lifestyle activity, such as cleaning and cooking. The result is your total daily energy expenditure or TDEE. Although individual levels vary based on genetics and biological differences, this number is a good estimate.

Calculate a Safe Calorie Deficit

One pound equals approximately 3,500 calories. To lose 1 pound per week, you must create a deficit of about 500 calories per day. For most runners, it’s difficult to lose weight faster and still maintain adequate energy for training. Also, studies show that people who lose weight gradually are more likely to keep it off in the long term.

To find your daily calorie budget, subtract 500 from your TDEE. If you eat this number of calories and do absolutely no exercise, you can still expect to lose weight.

Understand the Calorie Burn of Each Run

If you want to avoid out-eating your running, it’s crucial to get an accurate idea of how many calories you burn during each workout. Don’t blindly trust the output from treadmills, online activity calculators, fitness trackers, and weight-loss apps; they often show inflated the results. Instead, use a simple calculation:

Calories burned running = weight in kg x distance in km 

This equation is a good estimate for runs on flat ground; you’ll burn slightly more on an incline and slightly fewer on a decline. Your pace doesn’t matter; distance is the crucial factor. If you weigh 150 pounds, you’ll burn approximately 340 calories during a 3-mile run, whether you run it in 20 minutes or 40 minutes.

Track Your Calories

If you want to bump up your training and lose weight at the same time, it’s crucial to keep an eye on calorie intake. Download an app to your phone such as MyFitnessPal or Lose It!, and track everything you eat. Be brutally honest with yourself, and take the time to measure your portions carefully. Eyeballing your foods is a recipe for failure; what you think is 1 cup of pasta could be 2 cups or more.

Decide When to Eat Back Running Calories

For runners, the trick to weight loss is to maintain a caloric deficit without depriving your body of essential energy. On days that you don’t run, eat only the calories in your daily budget. On the days you do run, you can add the calories burned to the budget. If your calculated budget is 1,500 calories and you burn 300 calories during a run, for example, you can eat 1,800 calories and still maintain a 500-calorie deficit. 

This process sounds easy, but if you’re a beginning runner, or if you’ve just started to ramp up your training volume, intensified hunger can make this a challenge. Besides, the hard work of running can make you feel justified in indulging. Unfortunately, three or four slices of pizza can erase both a 300-calorie run and a 500-calorie deficit.

For this reason, it’s crucial to track calories. 

How Low is Too Low?

As your body becomes accustomed to increased mileage, the feelings of hunger will dissipate. When this happens, it can be tempting to avoid eating back your exercise calories to lose weight faster. 

This strategy might be OK if you’re only running short distances a couple of times per week. If you’re increasing daily mileage, running more days per week, or adding in long runs, however, use extreme caution. At this point, you need to consider the net calories that are available to your body.

Consider an example: 

If you have a BMR of 1,800 calories, you burn about 2,160 calories during regular daily activities (TDEE). To maintain a 500-calorie deficit and lose 1 pound per week, you must net 1660 calories per day. If you eat those 1,660 calories and burn 1000 calories on a long run, that leaves only 660 net calories available to your body. Since your body requires 1,800 calories to maintain basic functions, it will turn to other sources of fuel: fat and muscle.

Chances are, your body can tolerate this low net calorie level a few times without adverse effects. If you persist, however, it will respond with increased feelings of hunger. Soon, you will notice a drop in running performance, extreme fatigue, and an increased rate of injury.

The trick is to find a calorie intake level that: 

• Gives you enough energy to complete your training runs 

• Helps you manage hunger 

• Maintains a calorie deficit 

This result is different for everyone, depending on biology and daily activity levels. You might find that you need to increase your daily calorie budget to match your BMR to feel satisfied and maintain performance. That might result in slightly slower weight loss, but the process will be more pleasant and manageable. Another strategy is to eat back a portion of the calories you burn on a run until your hunger goes away.

If you’ve ever been surprised to see a higher number on the scale after weeks of running, it’s time to take action. With the right calorie balance and careful attention to performance, you can lose weight without sacrificing your training.

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